For those not familiar with permaculture, edge is the boundary between two elements. Examples of edge include the boundary between land and sky, water and sky, or water and land.
Edge is where all the action takes place. Fish congregate around structures in a lake and not at some neutral middle point in a lake (if they do, it is always around a temperature boundary). Deciduous trees generally lose their leaves from the outside edges first where the wind gets at them and knocks them loose. The nutrients from your food are absorbed into your body via the stomach wall and intestinal walls – ie. an edge. Gas exchange in hemoglobin occurs via the cell wall.
However, the importance of edge is not limited to the biological world. If one looks, the same patterns are found in the social world, for better or for worse. Health insurance did not arrive in Germany in1883 via a sudden kind-hearted decision of policy-makers. It came from a movement that started as a fringe and came to define the course of that nation’s history. Similarly, when universal suffrage was guaranteed in the United States in 1965 (ie. guaranteeing voting rights for Black voters), it again was not the result of the kind acts of powerful elites. It was the result of a “fringe” that spread its ideas; and those ideas came to define the society as a whole. (The same can also be said of regressive elements in society – eg. fascism.)
With this in mind, the permaculture “fringe” can understand its role in its attempt to change the structure of our societies. This “fringe” has reached its its tipping point in Australia and is now mainstream. In the world of international development aid, permaculture (or permaculture systems operating under a different name) are now recognised as the only design systems that can yield a truly sustainable result, and, as such, are right on a tipping point in that sphere.